1. Field of the Invention
This invention relates to power excavating equipment and its arrangement within a tunneling shield.
2. Description of the Prior Art
The power excavating equipment of the present invention is similar to the power excavating equipment disclosed by U.S. Pat. No. 3,556,599, granted Apr. 11, 1975, to Tyman H. Fikse, in that forward and rear and up and down movements of a digging tool are effected by means of a multipod of double-acting hydraulic cylinders. U.S. Pat. No. 3,966,256, the several patents mentioned therein, and the prior art that was cited and/or considered by the Patent and Trademark Office and listed at the end of the patent should be consulted for the purpose of properly evaluating the subject invention and putting it into proper perspective.
U.S. Pat. No. 3,612,609, granted Oct. 12, 1971, to Josef Reuls discloses an excavator which comprises an elongated boom which is mounted at its rear end for universal movement and is moved up and down and sideways by a plurality of cylinders. However, the boom is extended and retracted by a hydraulic cylinder incorporated within the boom. The digging tool, the hydraulic cylinder within the boom, and its immediate support structure, are rotated within the boom for changing the sideways attitude of the digging tool. Additional patents which should be considered for the purpose of putting the present invention into proper perspective are U.S. Pat. No. 4,026,604, granted May 31, 1977 to Mitsuteru Motomura, Chiaki Kojima, Hiroshi Ohta and Akira Nemoto; U.S. Pat. No. 4,043,137, granted Aug. 23, 1977, to Hans Jutte, Siegmund H. F. L. M. Banbendererde, Adolf Foik and Reinhard E. J. Bokemeyer; and U.S. Pat. No. 4,070,772, granted Jan. 31, 1978, to Mitsuteru Motomura, Chiaki Kojima, Hiroshi Ohta and Akira Nemoto.